The German patent DE 1113788 B has disclosed an endoscope showing a detached light source, the light of which is coupled into the endoscope by means of an optical waveguide and guided from the proximal end of the endoscope comprising the eyepiece to the distal end of the endoscope. Here, the endoscope is typically situated in a body cavity and emits the supplied light at said location in a substantially single direction for the purposes of illuminating the body cavity. The significant heat generated by the detached light source cannot lead to the patient being harmed as a result of the detached light source. Furthermore, the handling of this endoscope was found to be comfortable since the waste heat of the light source does not lead to significant heating of the endoscope.
The laid-open application DE 10 2011 054 031 A1 has disclosed an exoscope which serves for observing and illuminating an object field on a patient from a location away from the body of the patient. By means of a detached light source, the light for illumination purposes is supplied to the exoscope by means of an optical fibre cable and transmitted within the exoscope to the distal end comprising the head part with the aid of optical fibres and used at said location for illuminating the object field. Here, there are two exit openings for the light at the head, into which openings two partial bundles of the optical fibre bundle arranged in the exoscope open.
DE 10 2007 063 262 A1 has disclosed an illumination device for generating light for endoscopy or microscopy. In order to avoid the problems of the heating of the light source including an array of LEDs, said illumination device shows a plurality of cooling devices using heat pipes. This cooling was found to be very complicated.
Endoscopes with a variable, adjustable viewing direction are known from EP 2 263 519 A2 and EP 2 446 810 A1. These endoscopes require a precisely adjusted illumination of the region in which, depending on the set viewing direction, viewing takes place. Here, two options are presented. Firstly, there is large-scale illumination of the whole possible viewing region. Secondly, it is suggested to select not only the viewing direction in a selective manner but also to additionally adapt the illumination direction in a selective manner and parallel thereto by virtue of an optical waveguide at the distal end of the endoscope also being swiveled therewith and the illumination direction being modified thereby. This solution was found to be very complicated mechanically and requires a significant volume in the region of the distal end, significantly restricting the introduction of such a variable illumination into endoscopes with a small tube diameter. The problem of the heat load in the region of the light source clearly emerges in the case of the large-scale illumination.
Furthermore, the US patent application US 2006/0171693 A1 discloses an endoscope which includes a plurality of light sources, separated from one another, in the handle thereof, which light sources are respectively connected to a dedicated optical fibre bundle and respectively couple the generated light directly into the respectively assigned optical fibre bundle. Each optical fibre bundle subsequently transmits the light to the distal end thereof. At the distal end of the endoscope, the distal ends of the optical fibre bundles, respectively in a separate manner, open into spaced apart surfaces for decoupling the light. The optical fibre bundles with the surfaces for decoupling are arranged uniformly around the central image transmission channel and radiate in parallel in the same direction at the distal end. This endoscope shows a very complicated design.